Closing price per share of company's common stock at balance sheet date

Name:	mchp_ClosingPriceOfCompanysCommonStock
Namespace Prefix:	mchp
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average period over which unrecognized share-based compensation costs for restricted stock awards and restricted stock units are expected to be reported.

+ Details

Name:	mchp_RestrictedStockUnitsWeightedAverageRemainingExpenseRecognitionPeriod
Namespace Prefix:	mchp
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The intrinsic value of share-based payment equity instruments, excluding stock options, outstanding during the reporting period as calculated by applying the disclosed pricing methodology.

+ Details

Name:	mchp_TotalIntrinsicValueOfRestrictedStockUnitsOutstanding
Namespace Prefix:	mchp
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The intrinsic value of share-based payment equity instruments, excluding stock options, that vested during the reporting period as calculated by applying the disclosed pricing methodology.

+ Details

Name:	mchp_TotalIntrinsicValueOfRestrictedStockUnitsVested
Namespace Prefix:	mchp
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

As of the balance sheet date, the aggregate unrecognized cost of equity-based awards made to employees under equity-based compensation awards that have yet to vest.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph h

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (i)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, using a decimal to express in number of years.

+ References

+ Details

Name:	us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition
Namespace Prefix:	us-gaap
Data Type:	xbrli:decimalItemType
Balance Type:	na
Period Type:	duration

- Definition

The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph b(2)(d)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(2)(iii)(2)

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix:	us-gaap
Data Type:	num:perShareItemType
Balance Type:	na
Period Type:	duration

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ Details

Name:	us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix:	us-gaap
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

Equity Incentive Plans, Share-based Payment Award (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		6 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Closing price of company's common stock related to calculation of aggregate intrinsic value of stock options (in dollars per share)	$ 31.11
Restricted stock units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Amount of unearned share-based compensation estimated to be expensed related to unvested share-based payment awards	$ 72.1		$ 72.1
Weighted average period of unearned share-based compensation expected to be recognized (in years)	2.07
Total intrinsic value of restricted stock units vested	7.8		18.5
Total intrinsic value of restricted stock units outstanding	$ 172.1
Closing price of company's common stock related to calculation of aggregate intrinsic value of stock options (in dollars per share)	$ 31.11
Weighted average fair values per share of restricted stock units awarded (amount per share)	$ 31.61	$ 23.45	$ 32.27	$ 23.49
Restricted stock units' weighted average remaining expense recognition period (in years)	2.12